The anti-tumor effect of bee honey in Ehrlich ascite tumor model of mice is coincided with stimulation of the immune cells.

Honey is thought to exhibit a broad spectrum of therapeutic properties including antibacterial, antifungal, cytostatic and anti-inflammatory activity and has been used for the treatment of gastric ulcers, burns, and for storage of skin grafts. The present study investigated the antitumor effect of bee honey against Ehrlich ascites tumor in mice and the possible mode of antitumor action. Peroral administration of mice with honey (10, 100 or 1000 mg/ 100 g BW) every other day for 4 weeks before intraperitoneal inoculation with Ehrlich ascites tumor (EAT, 1 x 10(6) cells) increased the number bone marrow cells as well as peritoneal macrophages, but not peripheral blood leukocytes nor splenocytes. The phagocytic function of macrophages as well as the T- and B-cell functions were also increased. Honey pre-treatment also recovered the total lipids, total proteins, as well as liver and kidney enzyme activities in EAT-bearing mice. In vitro studies on EAT cells demonstrated inhibitory effect of honey on tumor cell proliferation, viability % of tumor cells as well as the size of solid tumor. The present results indicate that the preventive treatment with honey is considerably effective against EAT in mice both in vivo and in vitro. The antitumor activity of honey may occur through the activation of macrophages, T-cells and B-cells.

Recovery of age-dependent immunological deterioration in old mice by thyroxine treatment.

On the basis that multiple interactions exist between thyroid hormones and immune system, and ageing is accompanied by changes in thyroid hormone secretion, it seems possible that thyroid hormones may be involved in the age-related immune dysfunction. The present study was conducted to evaluate in vivo and in vitro effects of thyroxine (T(4)) treatment on both cell-mediated and humoral immune responses of aged mice. In a trial to improve age-associated immune dysfunction, T(4) (0.2, 1.0 and 5.0 microg) was subcutaneously supplemented to BALB/c mice (over 18 months old) for 30 consecutive days. The present results showed that exogenous treatment of aged mice with T(4) was associated with a marked increase in serum T(4) level, and the total number of peripheral blood leukocytes as well as the total cellularity of thymus, spleen, peripheral lymph nodes (PLNs), mesenteric lymph nodes (MLNs) and bone marrow (BM). T(4) treatment also caused a significant increase in the total and differential numbers of peritoneal exudate cells (PECs), while it caused a slight increase in macrophages' phagocytic activity of PEC. Moreover, T(4) treatment elicited a statistically significant increase in both plaque-forming cell and rosette-forming cell responses. In vitro results showed that the addition of T(4) at concentrations of 0.001, 0.005 and 0.025 microg/well substantially potentiated the ability of splenocytes from aged mice to proliferate in the presence of concanavalin-A mitogen. Histological examination of thymuses from T(4)-treated aged mice revealed that the cortex was preferentially enlarged and repopulated with immature thymocytes. The present study postulates that thyroid hormones may be involved in the observed decrease in the immune responsiveness during ageing, and that T(4) treatment to aged mice is able to restore the age-related decline of the immune efficiency.